The 22-year-old made 69 appearances for the Saddlers before moving to the Ricoh Arena in 2008, and the League One outfit are set for a cash boost due to a sell-on clause in that deal.
"We've always made a point of helping the manager as much as we can, that's always been the case and the money would help us to help him a little more," Whalley told the Express and Star.
"We've not seen the financial agreement and all the reports are undisclosed. Maybe the payments are over 12 months or a longer period. We haven't seen the details but we await them with interest.
"There are some big clubs coming down to League One, even though some are under financial pressure, but we feel our budget is competitive.
"He was sold for more than Coventry City paid us but the point remains he would not have achieved that type of value if he'd stayed in League One. The club protected its investment and the club deserves credit once again, for showing we can give a player the chance to launch his career."